riskbycounty
FEMA NRI 1.19.0Updated Nov 2023 · Coverage 2014–2023Methodology

Hamilton County Disaster Risk

Hamilton County, Tennessee

FEMA Risk Rating

Relatively Moderate

National Percentile

93th

of 3,144 counties

State Rank

#3

of 95 (1 = highest risk)

Flood Risk

95th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Relatively High

Higher than 95% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Relatively Low

Higher than 71% of US counties

Tornado

Tornado and severe thunderstorm risk

Relatively High

Higher than 99% of US counties

Earthquake

Seismic activity and ground shaking risk

Relatively High

Higher than 96% of US counties

Hurricane

Tropical cyclone and hurricane risk

Relatively Low

Higher than 63% of US counties

Risk Overview

About Natural Disaster Risk in Hamilton County, Tennessee

Hamilton County's above-average disaster risk

Hamilton County scores 93.29 on the composite risk index, placing it firmly in the "Relatively Moderate" category—well above Tennessee's average of 52.45 and the typical U.S. county profile. Tornadoes pose the greatest threat here, with a risk score of 98.60, nearly maxing out the scale. This combination of flood, earthquake, and tornado exposure puts the county in a higher-risk bracket than most American communities.

Highest-risk county in Tennessee

Hamilton County ranks as Tennessee's most disaster-prone county, with a composite risk score more than 40 points above the state average. Its 98.60 tornado risk score is the highest in the state, and its earthquake risk of 95.67 reflects the county's proximity to seismic fault lines. No other Tennessee county faces this concentration of multiple high-severity hazards.

Far riskier than surrounding counties

Hamilton County's 93.29 risk score dwarfs that of nearby Hawkins County (55.76) and Marion County, making it a clear outlier in the region. While neighboring counties face moderate tornado and earthquake risks, Hamilton's exposure across floods, earthquakes, and tornadoes simultaneously is unique. The gap reflects Hamilton's urban density and position relative to major fault lines and storm corridors.

Tornadoes and earthquakes dominate

Tornadoes are your primary threat—Hamilton County's score of 98.60 means severe twister activity is nearly certain in any given year, particularly spring and early summer. Earthquake risk scores 95.67, reflecting the county's location near the East Tennessee seismic zone; while major quakes are rare, moderate tremors occur regularly. Flooding also ranks high at 94.91, especially in low-lying areas near the Tennessee River and Chattahoochee system.

Bundle comprehensive disaster coverage

Given Hamilton County's exceptional tornado and earthquake exposure, standard homeowners insurance is insufficient—you need separate earthquake and flood policies to be truly protected. Consider a windstorm rider to cover tornado damage, and ensure your flood policy covers your property type and elevation. Securing this coverage now prevents catastrophic financial loss when severe weather inevitably strikes.

Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor

Preparedness Guide

What to Prepare for in Hamilton County

Top Hazards by Exposure

  1. #1
    TornadoPrepare
    99th percentile
  2. #2
    EarthquakePrepare
    96th percentile
  3. #3
    FloodPrepare
    95th percentile

Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)

Risk Advisory: Hamilton County

Risk Verdict

At the 93th percentile nationally, Hamilton County sits in the upper half of U.S. counties for natural disaster exposure. At this risk level, having a documented household preparedness plan — not just awareness — is the meaningful next step for Hamilton County residents.

Hazard Breakdown

Tornado risk is Hamilton County's dominant natural hazard, ranked at the 99th percentile nationally under FEMA's National Risk Index. Earthquake ranks second at the 96th percentile nationally. Additional tracked hazards include flood (95th percentile), wildfire (71th percentile), hurricane (63th percentile).

Preparedness Context

Tornado exposure at the 99th percentile nationally makes Hamilton County a county where a battery-powered weather radio — not just smartphone apps — is a worthwhile household investment, given that mobile networks often fail during severe storms. Alongside tornado exposure, earthquake at the 96th percentile nationally means Hamilton County households face multi-hazard severe-weather seasons that benefit from a single integrated emergency plan covering both threats. In Hamilton County, tornado watches indicate favorable atmospheric conditions while warnings mean rotation has been detected — households benefit from understanding this distinction so they shelter immediately on a warning, not after seeking visual confirmation.

Regional Context

The Tennessee county average is 40.8 composite points below Hamilton County's score, a gap that reflects the county's elevated position in the state's hazard distribution.

Is your household prepared for Hamilton County's hazards?

Review FEMA's county-specific preparedness checklists and emergency planning guides.

FEMA Ready Guide →

Frequently Asked Questions

What is the natural disaster risk in Hamilton County, TN?
Hamilton County has a FEMA National Risk Index rating of Relatively Moderate, placing it in the 93th percentile nationally out of 3,144 counties. This composite score reflects the county's overall exposure to natural hazards including floods, wildfires, tornadoes, earthquakes, and hurricanes, weighted by expected annual loss and social vulnerability.
What types of natural hazards affect Hamilton County?
Hamilton County is evaluated for five major natural hazard types: tornado (99th percentile), earthquake (96th percentile), flooding (95th percentile), wildfire (71th percentile), hurricane (63th percentile). The highest-risk hazard is tornado at the 99th percentile nationally. These scores are derived from FEMA's National Risk Index, which analyzes expected annual loss, social vulnerability, and community resilience for each hazard type.
How does Hamilton County risk compare to the Tennessee average?
Hamilton County's composite risk percentile is 93th, compared to the Tennessee state average of 53th percentile. The state's overall risk rating is Relatively Low. This means Hamilton County faces higher natural disaster risk than the typical county in Tennessee.
Is Hamilton County at risk for tornado?
Yes, Hamilton County's tornado risk is at the 99th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Hamilton County is at the 95th percentile.
How is natural disaster risk measured?
FEMA's National Risk Index (NRI) calculates risk scores for 18 natural hazard types across all U.S. counties and census tracts. The composite score combines Expected Annual Loss (estimated dollar losses from each hazard), Social Vulnerability (demographic factors affecting disaster impact), and Community Resilience (ability to recover). Percentile scores rank each county against all 3,144 U.S. counties, and risk ratings range from Very Low to Very High.
Why is Hamilton County higher risk than average?
Hamilton County's composite risk score of 93th percentile is above the Tennessee state average of 53th percentile. This elevated risk is driven by tornado exposure (99th percentile), along with earthquake and flooding and wildfire and hurricane risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.
By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

Data Source

Risk data sourced from the FEMA National Risk Index (NRI). Risk scores are relative rankings (0–100) across all US counties — not absolute risk measures. Higher scores indicate higher relative risk compared to other counties.

Disclaimer: This data is informational only. It is not financial, insurance, or legal advice. Always consult a qualified professional before making insurance or real estate decisions.